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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Korean Chemical Engineering Research
Journal Basic Information
Journal DOI :
The Korean Institute of Chemical Engineers
Editor in Chief :
KIM JAE JEONG
Volume & Issues
Volume 27, Issue 6 - Dec 1989
Volume 27, Issue 5 - Oct 1989
Volume 27, Issue 4 - Aug 1989
Volume 27, Issue 3 - Jun 1989
Volume 27, Issue 2 - Apr 1989
Volume 27, Issue 1 - Feb 1989
Selecting the target year
Activity, Selectivity and Stability of Pt-Re Bimetallic Catalysts Supported on
-Alumina in n-Hexane Reforming Reaction
Woo, Seong-Ihl ; Noh, Ou-Sun ; Yang, O-Bong ; Kim, Young-Gul ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 729~729
The activities, selectivities and stabilities of bimetallic Pt-Re clusters supported on
-alumina were evaluated in the n-hexane reforming reaction. Reaction temperature and calcination temperatures were varied at
, respectively. Reduction was performed at
. Pt-Re/alumina catalysts were prepared by coimpregnating the aqueous solution of
. When the amount of Pt supported on alumina increased, the selectivity towards benzene increased, but the selectivity towards
isomers decreased. Pt-Re/alumina was more active in the hydrogenolysis reaction at
than Pt/alumina, resulting in the higher selectivity towards
com-pound. However, Pt-Re/alumina produced less
compound and more benzene above
than Pt/alumina. The activities and selectivities of Pt-Re/alumina were varied with different calcination temperatures, indicating that the formation of Pt-Re bimetallic cluster is dependent on the calcination temperature. The addition of Re on Pt improved the maintenance of activity by decreasing the deactivation rate.
Synthesis of Layer Nickel Silicate and Catalytic Activity for Ethylene Dimerization
Sohn, Jong-Rack ; Jeon, Jin-Ick ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 737~737
Two types of layer nickel silicate, nickel montmorillonite and nickel antigorite were synthesized by co-precipitation from an acidic solution of a nickel salt-sodium silicate mixture followed by hydrothermal treatment at
and 780psi. The structures of synthesized nickel silicate were examined by X-ray diffraction patterns and infrared absorption spectra. The nickel silicates thus synthesized were activated for ethylene dimerization by evacuation at elevated temperatures, giving two optimum temperatures,
. The acid site responsible for the catalytic activity is
acid at low evacuation temperature of
, while Lewis acid at high evacuation temperature of
. The crystallinity of the nickel silicates was improved gradually with the hydrothermal treatment, while the catalytic activities and surface area decreased with that.
Mass Transfer in a Wetted-Wall Column with Liquid-Liquid Laminer Flow
Park, Sang-Wook ; Yang, Sam-Seoug ; Kim, Jong-Hyun ; Asai, Satoru ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 744~744
Film- and continuous-phase mass transfer in liquid-liquid system was studied using a cocurrent laminar wetted-wall column of a modified form. The film-phase mass transfer coefficients were measured by dissolution of n-butanol, ethyl acetate and cyclohexanone in water, and the continuous-phase mass transfer coefficients measured by the transfer of
dissolved in continuous-phase of n-hexane and cyclohexane into the interface, where
disappeared by the instantaneous irreversible reaction with
in the aqueous film-phase. These coefficients could be analyzed by the penetration theory and were in good agreement with Beek-Bakker model.
Studies on the Relative Viscosities of Liquid-Liquid Dispersion Systems
Yang, Ji-Won ; Hur, Byung-Ki ; Mok, Young-Il ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 751~751
The relative viscosity of dispersion was investigated focussing the attention on the drop size distribution as well as the volume concentration of the dispersed phase:
is the volume concentration of the dispersed phase; A and B are functions of drop size distribution of the dispersed phase and viscosities of the continuous and the dispersed phases. In order to validate the proposed model, published data were applied to the model and were compared with calculated results. The errors between experimental viscosities and calculated values ranged from 0% to 3.86% depend-ing on the materials of dispersions. Also the same model has been applied to the emulsion system. Predicted viscosities of emulsions by the model agreed with experimental data reasonably well giving a maximum error of 4.1%.
Dilute Solution of Flexible Polymers in a Rectilinear Poiseuille Flow
Son, Young-Gon ; Park, O-Ok ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 759~759
The local shear viscosity of the linear dumbbell polymer between two parallel plate with a rectilinear poiseuille flow was given as a function of the lateral position
(center of the mass coordinate of dumbbell) from the center of the channel. This was obtained by neglecting the brownian diffusion term of
as induced from the fact that the configurational probability distribution with respect to
is unchanged at steady state. The average shear viscosity is increasing by increasing channel size. But upon the critical channel size the average shear viscosity is not increasing with channel size. The local first normal stress coefficient was given as a function of the lateral position, too. But in the center of the channel its value has a infinite value which should be corrected in the future.
The Optimum Impregnation Conditions of
Adsorber for Dry Desulfurization
Chung, Soo-Hyun ; Kim, Dong-Chan ; Park, Chan-Young ; Cho, Chong-Hyun ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 767~767
To use copper oxide as a dry desulfurizer the reactive adsorption capability was evaluated after it was impregnated in three types of spherical
possessing different pore size distribution. As a result, it was found that the reactive adsorption capability has a close correlation with the pore size distribution of the carrier, and that the carrier having even pore size distribution was able to impregnate copper oxide in high concentration. In this study, on the basis of unit reactive adsorption capacity, the optimum conditions were found to be the reaction temperature
, the sulfur dioxide concentration 2,000 ppm and the impregnation concentration of 6wt%, which was evaluated to the maximum value of sulfur dioxide 5.10g per 10g of CuO when the carrier ALO-3 was used. Based on the adsorption treatment capability, the carriers, KHT and X-5, were able to adsorb more sulfur dioxide than ALO-3 by 1.15-1.55g per 10g of CuO in the impregnation concentration of 14wt%.
Increase of Specific Surface Area of Carbon Fiber
Lee, Deok-U ; Lee, Jin-Gi ; Lee, Bo-Seong ; Yu, Seung-Gon ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 777~777
Isotropic pitch-based carbon fiber was activated with the mixture of nitrogen and super heated water vapor to increased the specific surface area and some activated carbon fiber shows a specific surface area of
. The increase of specific surface area seems to be caused by the enlargement of micropores of fiber surface to meso-pores, and it is believed that parts of inner pores have been exposed to outside. The weight loss of carbon fiber was pro-portional to activation time and temperature. The specific surface area of carbon fiber was linearly proportional to the weight loss at constant activation temperature.
Kinetic Approach to Growth of Ultrafine Particles by Chemical Reaction
Kim, Sun-Geon ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 784~784
Experimental and theoretical studies are reported on the growth of metallic particles during the reduction of metallic salts by borohydride. The increase in reaction rate by the increase in temperature or by the choice of the metallic salt which gives higher reduction rate shows a tendency of reducing the average size of particles formed. A model equation, called General Dynamic Equation, which considers all the terms contributing particle formation and growth processes including chemical reaction has been numerically solved by the method of moment transformation with other necessary equations. the solutions successfully support the experimental observations and also make the growth mechanism clear: more nuclei are formed at higher reaction rate and as r result, there remain fewer monomers available for the subsequent condensation on the nuclei. In this system coagulation of particles has been shown not to be so important in determining the size of growing particles.
Digital Control of Cell Mass Concentration in Continuous stirred Tank Bioreactor-Part1. Cell Mass Control Using Stochastic Adaptive Control Algorithm(ELS-STR)
Hwang, Young-Bo ; Yi, Gyeong-Beom ; Chang, Ho-Nam ; Lee, Kwang-Soon ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 794~794
Two types of digital control algorithm were experimentally examined for the control of yeast cell-mass concentration in a CSTBR(continuous stirred tank bioreactor). One of them is a high gain proportional control resulted from highly output weighted quadratic cost regulator. The other is a stochastic adaptive control named ELS-STR, which is a minimum variance controller with an extended least-squares method as parameter identifier. On-line estimation of the state variable, cell mass concentration, was carried out by measuring optical density of the fermentor broth. From experimental results, it was known that the performances of ELS-STR were better than that of conventional PID controller in cell mass control case.
Effect of the Membrane Potential on the Flux of Amino Acid through the Supported Liquid Membrane
Kang, Seung-Moon ; Woo, In-Sung ; Kang, An-Soo ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 804~804
The relationship between membrane potential and flux of amino acid has been analyzed for the counter-transport system of amino acid coupled to the various concentration of added electrolytes through the sup-ported liquid membrane. The liquid membrane contained Aliquat 336 as liquid anion exchanger in various solvents with different dielectric constants. For the supported organic liquid membrane, solvents with lower dielectric constants was favored so that flux of amino acid was increased against it. The membrane potential decreased with increasing potentiometric selectivity sequence of added electrolytes; however, the flux of amino acid increased. Above the detection limit the membrane potential increased with increasing concentration of added electrolytes; however, the flux of amino acid decreased.
Experimental Studies on Flocculation of Solid Particles and Solid-Liquid Separation with Couette Flocculators Part 1. Optimum Flocculation Conditions
Jeon, Gwi ; Choe, Chang-Gyun ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 812~812
The study on flocculation in a Couette flocculator showing Taylor vortices and subsequent solid-liquid separation characteristics was conducted experimentally. In this study silica or kaolin suspensions in water were used to investigate flocculation by cationic polymers. In the present experiments the optimum retention time was found to be about 150 seconds. The optimum Taylor number reached a constant value, when the suspension concentration was less than
. For the suspension concentration of
, the optimum Taylor number decreased with an increase in suspension concentration. With these results a correlation of the optimum Taylor number was obtained as a function of the suspension concentration and the flocculant concentration. The resulting Camp number at optimum conditions was found to scatter in the range of
The Casting Method for Producing Solar-Grade Polycrystalline Silicon Wafer(II) -An Experimental study by the Resistance Heating Method and the R.F. Heating Method-
So, Won-Wook ; Yoon, Kyung-Koo ; Moon, Sang-Jin ; Yoon, Poong ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 823~823
Two separate casting apparatuses were designed and fabricated using the resistance heating method and the RF heating method, respectively. Graphite and fused quartz were used as crucibles for the method, respectively. Their inner surfaces were coated with
layer for the protection of the crucibles and the ingots. The impurity level, structure, grain size, and dislocation concentration of the polycrystalline silicon wafers which affect the efficiency of the solar cell were measured for each method and compared with the reference values published for high efficiency solar cells. The present casting method provided satisfactory results regardless of some difference in the physical properties de-pending on the methods adopted above.
A Study of CO Oxidation on the Pt Loaded Anodized Aluminium Tube-Wall Reactor
Yoo, Byoung-Kang ; Choi, Myoung-Jai ; Lee, In-Wha ; Hong, Suk-In ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 833~833
Aluminium oxide film was formed inside tube-wall by electrical anodic oxidation and Pt was loaded on the film for oxidation of carbon monoxide. The anodic films were turned out porous
having the structure of amorphous
and polygonal cells from the analysis of XRD, FT-IR, SEM, and SEM-EDX. The aluminium tube anodized at 18V for 90 minute was selected for the test reaction of the oxidation of CO. The model proposed by Senkan et al. was adapted in our study and tested against experimental data. It was demonstrated that the reactor was not diffusion limited and that kinetic resistance must be included in this study.
Heat and Mass Transfer Characteristics in a Solid-Suspended Bubble Column with A Draft Tube
Park, Chan-Jin ; Do, Dong-Seop ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 845~845
Heat and mass transfer characteristics in the circulating slurry suspension by bubble-agitation in a bubble column with a draft tube were studied in a 8.90cm I.D.
high acryl column. Heat transfer coefficients increased with increasing superficial gas velocity, particle size and the concentration of particles and were larger than those without the addition of particles. The volumetric mass transfer coefficients increased with an increase in superficial gas velocity but decreased with an increase in particle size and concentration of particles and were smaller than those without the addition of particles. To explain these phenomena, the energy dissipation rate estimated from the energy balance was combined with the surface renewal theory and Kolmogoroff's isotropic turbulence theory to predict the theoretical heat transfer coefficients. Also the volumetric mass transfer coefficient was derived from the eddy cell model and energy dissipation rate with specific gas-liquid interfacial area. These theoretical equations could predict the tendency of the experimental data of heat and mass transfer very well.
Improvement of Filtration Characteristics of Diatomite Filter-Aid by Polyelectrolyte Adsorption
Yun, Seok-Ho ; Na, Jong-Bok ; Gwak, Eun-Yeong ; Seo, Dong-Seok ;
Korean Chemical Engineering Research, volume 27, issue 6, 1989, Pages 855~855
Diatomite filter-aids coated with polyeletrolytes such as C.M.C, gelatine and polyacrylamide is adsorb-ed, were used in the vacuum precoat filtration of dilute ink and coffee slurries. The amount of adsorbed polyeletrolytes increased proportionally with the ratio of polyelectrolyte/diatomite, and the relation of adsorption equilibrium concentration and adsorption amount is well fitted with Freundlich equation. The polyelectrolyte adsorption on diatomite enabled to filler out ultrafine particulate matter which would otherwise call for much finer grades of diatomite. The turbidity of filtrate was improved with increasing amount of polyelectrolyte adsorbed. The polyelectrolyte adsorption on diatomite decreased the filtration rate.